


Perfect Sister

by ll72



Category: Buffy the Vampire Slayer (TV)
Genre: Anal, Don't read this if you're underage, F/F, Hardcore, I've warned you., Incest (sort of...), Lesbian, Robot Sex, Seriously only read this if you're into graphic sexual descriptions, Sex Toys, Sistercest (sort of...), explicit - Freeform
Language: English
Status: Completed
Published: 2018-06-04
Updated: 2018-06-04
Packaged: 2019-05-18 07:56:56
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 7,072
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14848787
Author URL: https://archiveofourown.org/users/ll72/pseuds/ll72
Summary: Dawn discovers the Buffybot is the perfect sister





	Perfect Sister

Dawn is over the age of sixteen in this story

*

"I'm a terrible sister, Dawn, the absolute worst," said Buffy sweetly as she picked up some of Dawn's clothes, which were scattered on the teen's bedroom floor. She looked briefly at each item she picked up before either placing it in a pile to be taken down for laundry or carefully folded it to replace in the drawer. "I take no notice of your needs, I'm bossy and snarky and always telling you what to do. I hog the remote and act like I own the whole house and you're my slave." She opened the drawer to put in the refolded clothes and noticing that the pile of Dawn's T-shirts weren't one hundred percent straight fluffed and ordered them so that they were so neat they looked like a square block. "I really am a terrible sister. I shall try and be better if you forgive me."

"I forgive you," Dawn said magnanimously, it always made her feel good to be the bigger person and forgive, "but you are a terrible sister." You went and died on me.

The Buffybot looked so stricken that she wasn't the perfect older sister for Dawn that for a second the young teen thought it was about to burst into tears. It could and it could eat and drink and fight and do virtually everything a real Buffy could do, except be human. Spike had fucked her, but he'd still been in unrequited love with the real Buffy. Willow had reprogrammed her so that she could pretend to be Buffy to the new High School Principal, but she still mourned her friend and avoided the 'bot when she could. Dawn was smart enough to know the Buffybot wasn't real, but there was something comforting about having her around and being the sister Buffy should have been. The 'bot seem programmed to be receptive to her desires - even to the extent of tidying her room and performing the younger Summers' chores.

"Do you want me to do anything else?" Buffy stood with the dirty laundry in her hands, "Some milk and cookies? I could do your homework?" The last, though meant well, wasn't as helpful as it sounded. When Dawn had previously tried it she found Buffybot's skills hadn't quiet advanced to even basic adding never mind algebra, resulting in Dawn's first ever 'F'. Even worse it had meant the Buffybot going into school to see the Principal and do the big sister thing, with Dawn fidgeting in embarrassment, as the bot promised to keep an eye on her and make sure she kept up her studies.

"No," the teen shook her head, "I've got a test tomorrow and they'd notice if it was you not me there."

The expression of concern on the Buffybot's face was both touching and comical, it was almost as if Dawn had said she'd got an incurable disease. And the Buffybot's further reactions were not dissimilar, she reached out to take Dawn's temperature and lifted her wrist to take her pulse. "You seem hot and your heart is racing, I should ring in and tell them you are sick."

"The reason my heart is speeding and I'm a teenier hotter than normal, is that you've just made me an extra strength coffee," the Buffybot's hot drink making skills were, also, at best passable. She seemed to think that coffee wasn't coffee unless it was strong enough to put down an elephant. "Anyway the test's not until tomorrow."

"Oh," said the Buffybot, showing much more concern than the real Buffy ever had. "Are you sure you are alright? I'd be a really bad sister if I didn't help." She put down the laundry, or rather dropped it in a heap, and got onto the bed with Dawn, crossing her legs and looking at the younger teen, "I should help you revise."

"It's not necessary," said Dawn, who'd actually done all the work she intended to do for tomorrow's test - she didn't want to overload her brain.

The Buffybot nodded enthusiastically, part of being a great big sister was never to argue or contradict Dawn. She pushed back Dawn's long hair and reached for her shoulders, "You are tense. I could give you a massage."

Actually that sounded kinda nice. Dawn had never had a massage, but her friend Janice had got one with her Mom and older sister when they were on vacation and had raved about it for at least a couple of weeks. "Okay," she nodded, "I am a little stiff and tense, y'know with you dying and everything."

"I'm good at giving massages," the Buffybot always found references to her being dead a little confusing and so, as she did with everything she couldn't understand, she ignored it. "Lie down, please."

"Okay." Dawn said a little bemused. When Janice had her massage she'd been sitting on a sun chair, sipping a (non-alcoholic) cocktail whilst a Thai masseur chatted away in broken English and rubbed her shoulders. It looked like the Buffybot was going to try something different. How different Dawn was about to find out...

"You should take off your top," said the Buffybot.

"My top?" Dawn asked.

"So I can massage you," said the Buffybot in a voice of calm reasonableness.

Dawn mentally shrugged but undid her blouse, pulling it off and dropping it on the floor; the Buffybot could pick it up when she was finished. She wondered whether to take her bra off as well and was still considering when she saw two pieces of clothing flutter past her eyes beside her top, the Buffybot's bra and sweater. "What are you doing?" Dawn asked in surprise.

"Spike always liked me to be topless as I massaged his back, he said it gave me a better grip," the Buffybot said innocently. 

Dawn shook her head in exasperation, the Buffybot's desire to be Spike's sex slave might have been reprogrammed out of her, but there were still traces. She was about to tell the 'bot to get dressed again and then reconsidered; it wouldn't do any harm to have her topless and sometimes reinstructing the 'bot to go against what she'd already been told to left her so confused she went into full panic-mode. "Go ahead," said Dawn.

"I think you're the best sister ever," said the Buffybot as she began to rub at Dawn's back and shoulders, "I should give you a massage every day. Oh I don't... oh, I am such a terrible sister."

Dawn sighed contentedly as the Buffybot continued to speak, her words like a stream of consciousness. The brunette ignored the blabbering and enjoyed the touch, whatever else you could say about the relative strengths of Buffy vs the 'bot, Dawn doubted her sister could give a massage as good as she was getting. The Buffybot's hands moved expertly up and down Dawn's body, removing knots of tension the teen didn't even know she had. The teen brunette could see how Janice raved about her massage, but she now also thought her bff, had been short-changed.

"...and I know I don't spend enough time with you, I'm going to spend more. And I shouldn't complain about your friends either, in fact I wish I had someone as cool as Janice for my best friend. There's Willow I suppose and Xander, but they're as much your friends as mine, I mean probably more, and Spike. I don't know why Spike had a thing for me when you were around, not that I like Spike with his washboard abs, but you're much prettier than I am. Do you want to take your pants down now and I can massage your butt?"

"W...what?" Dawn had been drifting, vaguely listening to the Buffybot's conversation in the same way you listen to your favourite tunes on your walkman when dozing in the back seat of a car on a long journey.

"Do you want to take your pants off so I can massage your butt? Or I can take them down for you if you want," said the Buffybot cheerfully.

"Massage my butt?" Dawn asked incredulously.

"Oh yes, it's not a proper massage unless I massage your buttocks. They get very tense and I'm a very good masseur," the Buffybot said with perhaps just a hint of unprogrammed pride.

Dawn paused for a second, what was the harm? She certainly couldn't complain about the massage so far, the Buffybot was an expert. And it wasn't if she was really her sister, or even real... "Okay," she said, "You can massage my butt." She reached under her body and undid her jeans, pulling them past her hips. 

The Buffybot hands met hers and pulled the denims the rest of the way off. "You should take off your panties as well. I can't give you a massage if they're still on."

"Okay, sure," Dawn nodded and reached for her underwear. The Buffybot was quicker, sliding the teen's panties down so quickly that it was like she'd been planning it even before Dawn consented. 

Dawn had been expecting the Buffybot to resume the massage straight away, but it didn't. Instead the bed rocked as if the blonde was struggling with something. Dawn was about to lift her head and look round when the Buffybot's leather pants and thong sailed passed Dawn's head to land on the floor. The teen did turn round, gawping at the Buffybot's nakedness, not that it wasn't kind of attractive and not as icky as it should have been given that she was modelled after her sister. Or sort of sister given that Dawn hadn't actually been born from the same parents or any parents at all come to that... "What are you doing?" the teen frowned

Ask a silly question.... "I'm getting naked to massage your butt. Spike always said the best massage is a nude massage," the Buffybot smiled innocently.

"He would," replied Dawn, who, whilst still a virgin, wasn't as innocent as the ex-sex doll

"You should remove your bra as well, then I can give you a super massage" the Buffybot was already reaching down as if she had no conception Dawn would disagree.

The teen knew when she was beat, "Okay..." She reached up to unhook, but the Buffybot's was already there. Their fingers connected. It was only a brief touch, before Dawn put her hands back and the 'bot continued to undo her bra, but the teen felt a surprising frisson. She shivered as the 'bot pulled away the bra, and it wasn't due to the cold - it was only early Fall. She felt warm as well, her skin flushed and heated that was nothing to do with temperature. And it wasn't only her skin that was reacting as the Buffybot's hands went over, her pussy was tingling and excited, the way it felt as she imagined Spike kissing her and slipping into her bed at night. She tried to ignore the sensations. 

And then the Buffybot began the massage again. If Dawn had thought it was relaxing and tension reducing before, now it seemed sensual and exciting. The Buffybot was sitting astride the teen's legs as she worked her hands over Dawn's butt, kneading the flesh and pressing her fingers hard and deep into the flesh. That would have been enough to make the brunette teen wet, but the Buffybot was doing even more. She'd positioned herself so that she was astride Dawn's leg and every time she pushed forward to slide her hands over the teen's butt, her pussy slid at the Dawn's leg. Dawn could feel its gentle touch as the lips glided over her skin. It was making her so hot and horny.

The Buffybot, unsurprisingly, seemed oblivious to effect she was having. "If you're having a test tomorrow I need to make sure you're ready for it. Are you sure you don't want me to call you in sick? I could tell them you have something contagious like the Black Death so they don't come round to check and I could feed you ice-cream all day so it'd be like being really sick without being really ill. But if you're going in I should make your favourite meal. I mean I always make your favourite meal every night, but I'd make it even more favouriter and you could have the remote control."

"Mmnnn," Dawn moaned in pleasure, it was impossible to ignore the sensations flowing through her, they were making her so horny. As soon as the 'bot was gone Dawn would be on her back, stroking her pussy and making herself cum again and again. She knew it was wrong to be turned on by someone who was the exact physical duplicate of her sister, but the 'bot wasn't real she told herself and even if it was wrong, that didn't help the fact she was turned on. 

The Buffybot's hands kneaded at her ass, squeezing and playing with it. God knew what types of massage Spike had taught the blonde 'bot, Dawn thought, but he must have come away from them without a knot in his body and a cock as hard as iron. Of course Spike had an advantage that the 'bot knew exactly how to take care of the latter problem. 

"Mmnnnn, ooooohhh," Dawn couldn't help but groan in joy as the 'bot's hands pulled at her cheeks, easing them apart and squeezing the tension out of them. "That's right," she murmured, "...there..."

"This should make you ready for the test," the Buffybot continued her almost non-stop commentary, "You'll ace it of course, because you're so bright. Not like me, I'm a dumbo, Mom always said you were the clever one in the family and she was right. You're also the pretty one and the funny one and the one everyone looks up to, even me. I sometimes think you should be the big sister, you're so cool, and I should be the little sister so that I can properly be in awe of you. Should I eat your pussy now? I think you'd be great big sis..."

"W... what? What was that? What did you say?" Dawn would have sat straight up if the Buffybot hadn't been on her legs.

"I should be the little sister and look up to you. We can do that if you want. I could call you big sis... unless you think that would mean I think you weigh too much, oh Dawn, I'd never think that. You're body is perfect," the 'bot let out a further stream of consciousness.

"No...before that, about my pussy," Dawn managed to force hers body to twist so that she could half-see Buffy.

"I was wondering if you wanted me to eat your pussy," the Buffybot smiled at the teen, "When I massaged Spike I always sucked his dick after I'd massaged his ass as his massive prick was always so hard. But as you don't have a donkey sized dong like Spike I thought the best thing I can do is eat out your cunt."

The thought of Spike having a huge dick sent the teen's libido even further into the stratosphere. He was her crush, even if he wanted her sister more than her. She would tell herself later that was the only explanation for what she said next. 

"Yes."

The words might have been a surprise, especially to herself, but Dawn didn't feel any regret in saying them. She'd never gone too far with a guy, not beyond having her tittie felt under her sweater and yet she was saying yes to have her pussy licked by a doppelganger of her sister. She should feel bad about it, not turned on. But it was the horniness that was winning out on her, it would have been different if the Buffybot was real and human (or even mystical), but she wasn't. The teen turned round the 'bot lifted herself off her legs to allow her. Dawn inwardly gulped, knowing that she had seconds to say this was a mistake, though it would confuse the 'bot though and send her into spinny panic mode. The teen spread her legs a little, the blonde automaton above her moving her own legs apart so that her knees rested against the outside of Dawn's thigh. Dawn looked up, the Buffybot was an exact replica of Buffy, even down to the dimples. She didn't want to see her face anymore, "Eat me," she said.

"Sure thing sister," said the Buffybot cheerfully. 

The blonde moved position, getting in between Dawn's legs and placing her hands on the inside of the teen's thighs pushing them out so that she had plenty of room. Dawn complied with the 'bot's unspoken instruction and as blonde's hands moved she spread her legs. The Buffybot paused for a moment, her face hovering above Dawn's shaven slit. "Oh you have the prettiest pussy. I knew it would be. It looks so good to eat, yummy."

"Eat it," said Dawn, fearing that otherwise the 'bot would still be rambling on when Tara and Willow returned from all day shopping trip in LA.

"Oh yes, of course. I'm not satisfying you, I really am a bad sister," the Buffybot continued.

"Just eat it," moaned Dawn in frustrated anticipation.

For a moment she thought the 'bot was going to continue chatting and whilst Dawn wasn't against having praise heaped on her, there was a time and place for it. Luckily the blonde robot seemed finally to get Dawn's not too subtle hint she wanted licking and dived down. 

Dawn had never been lapped at before. She knew a few of the girls in her class had been gone down on by their boyfriends and they all said it was great. And she played with her own pussy (a lot) and enjoyed imagining it was Spike with her. So she was hoping it would be good.

It wasn't.

It was fantastic.

She had forgotten the Buffybot was designed for sex, and on top of that she was the new and improved version of a previous model made to please, any issues ironed out so only the kinks remained. The robots tongue might not be real, but it certainly didn't feel fake and nor did her fingers as they slid apart the teenage slit and slid in. Dawn gasped as both tongue and fingers went into her virgin hole. Her hands reached out and she gripped her bedding, grabbing it like if she didn't she'd plummet to her death. The 'bot's tongue slid up and over her wet slit, her fingers holding apart the hole to allow it easy entrance. Hard and fast, like she was desperate slurping up a melting ice cream the blonde's tongue slurped.

"Oooohhh myyyy Godddd," Dawn gasped as the blonde's tongue found spots that the teen didn't even know existed. There was no pause from the 'bot, as Dawn shuddered and squeaked, her tongue continued to work its way in and out and round the slit, concentrating on those spots which made Dawn jump the most. The teen's head bounced back, smacking against her mattress, her hair splayed wildly out behind her. "Oooohhh, fuuuckk, ooooohhh Godddd, this is the best... oooohhhh, urrrrhhhh."

The Buffybot didn't reply, at least with words, just continuing to slurp out Dawn's pussy. Her fingers slid from now open pussy, though the tongue continued to swirl and sweep round the cunt. For a moment or two the blonde's hands rested on the teenager's thighs, stroking the hot skin, the digits which had been in Dawn's hole leaving wet traces of girl cum over the flesh. Then leaving one hand in place the Buffybot moved the other to just above the cunt, lowering the thumb to rub circularly over the brunette's clit.

"Hhhuuhh, hhhuuuhhh, uuurrhhh," Dawn's back arched as the pleasure tore into her like an electrical current. She'd never felt anything like it, to say the buzzes in her pussy were pleasurable was like saying being out in the North Pole during a blizzard was cold; it was true but didn't really do the sensation justice. She gripped the bedding even tighter, "Oooohhh, hhhhuuhhh, don't stop, don't stop!"

The 'bot did as her 'sister' said and carried on slurping, licking with undoubted enthusiasm as Dawn's pussy. The teen's body bent and arched as the blonde's tongue brought her to places she'd never been before and would definitely want to return to. Buffy tongue shot up and along the slit, driving the juice out and over the lips, leaving them gleaming wet, sparkling under the overhead light. Dawn squealed again, her hands reaching up to grab her boobs and squeeze them hard, the nipples hardening like little iron helmets as her fingers gripped into the flesh around them.

"Are you enjoying? Am I being a good sister?" the Buffybot looked up from the teenager's twat, the young brunette's juice staining her lips as she smiled dumbly.

"Yes," panted Dawn, her breathing still out of kilter, "Lick me more."

"Okay. I want to be a good sister and eat your cunt," the 'bot smiled even more widely before bringing her mouth down again.

"Oooohhh, fuuuckkk, oooohhhh," Dawn grunted out immediately as the automaton's tongue shot out over her cunt. It swished up and down, swirling over and into the gap, before racing up to find the clitoris. The teen gasped even more loudly as 'bot tongue started to press at the hood and down at the bud beneath, a finger sliding into the hole itself to replace the tongue. The blonde licked faster and harder, pressuring the clit and sending waves of excitement crashing through the teenager like stormy waves against a harbour pier. Dawn squealed some more, it was like she was ascending to heaven, she had never felt such pleasure; she now knew why Buffy used to have early nights when Riley came round - though whether he was as good as the 'bot she couldn't say.

"Ooohhh, ooohhh, don't stop, oh my God, don't ever stop," the teen shrieked. The 'bot was used to obeying whatever was said and carried on lapping and licking, her tongue exploring new places as it returned to burrow down the teen's cunt, leaving the stimulation of the clitoris to a well placed thumb. Dawn bucked again, an orgasm hitting her so intensely her muscles seemed to take a life of their own and send her into paroxysms of joy. The explosions of pleasure seemed to burn, so hot were they. Her mouth opened. She screamed, "Aaaarrrrghhh, fuuuckkk, oooohhhh myyyy fuuuuckk!!!"

The 'bot looked up, concerned. "Are you alright Dawn? Spike never used to scream."

"He wasn't a girl," Dawn explained.

"And girls scream where they're afraid or hurting as they're not manly like Spike." the Buffybot nodded sagely, before frowning, "... but I thought I was doing good."

"You were," Dawn pushed herself onto her elbows so she was half sitting. "We scream for other reasons as well, like when we're enjoying things."

"Like ice-cream? You never scream when I feed you ice cream? Am I getting the wrong flavours? Oh Dawn I'm sorry you must think I'm a terrible sister not to know you're favourite."

"Chocolate chip," Dawn confirmed quickly before the 'bot decided to switch to vanilla or raspberry or even worse decided to drop ice cream from the menu altogether. "But I mean we scream when good things happen to our pussies. Didn't you scream when Spike used to screw your pussy?"

Again the 'bot looked confused. "He never banged me in my pussy, he said it wasn't the right hole. He always nailed me in the ass." She smiled proudly. "I did scream then. It was fun, you're right Dawn. You're very clever."

Dawn blinked in surprise, though she really shouldn't have been, despite appearances Spike wasn't a good boy who you could bring home, but a violent, depraved vampire who couldn't kill. She did think he was hot though and kinda wished it had been her ass the demon had been ploughing. It was also nice to be sharing secrets with Buffy, even if it was a fake Buffy who was dumber than your average blonde, "So you liked it up your ass?"

"Oh yes, Dawn, it was fun. I would still do it, even though Willow told me I don't have too. You could do it too," the 'bot smiled.

"With Spike?" Dawn asked.

"Oh no, Willow says Spike is evil. He's not allowed to use his big dick, only go out on patrol with him and watch him kill things and tell passers-by I did it," she explained; making Dawn think that Willow should readjust the 'bots programming before she confessed being a mass murderer to a nearby cop. The 'bot continued happily, "You could do it with me."

"With you?" Dawn asked.

"Oh yes, it'd be fun, something we can do as sisters," she clapped her hands together enthusiastically as if she was talking about them getting matching sweaters rather than lesbian semi-incestuous butt-fucking.

For a few seconds Dawn considered, anal fucking when you were still technically a virgin seemed like a big step, doing it with another girl was a bigger one, and when that girl looked like (and thought she was) your sister the step was bigger than Neil Armstrong's leap. "Sure," Dawn nodded. If the 'bot had done it with Spike and loved it, Dawn was sure she'd enjoy it the same, after all she wasn't complaining about either the massage or the pussy licking which had gone before, "Let's do it."

The Buffybot almost bounded from the bed, such was her excitement. She rushed towards the bedroom door and suddenly stopped, an expression of disappointment and confusion clouding her face. "I don't have a cock, do you?"

Dawn grinned, "I know where to find one, wait here."

Leaving the perplexed 'bot in her room she swiftly skipped to Willow and Tara's. She headed to the chest of drawers in the corner and opened the middle one. She'd found the two lesbian lovers toy stash when she'd be searching around to see if they had any decent clothes she could borrow - which given their fashion sense was, admittedly, unlikely. She looked at the toys, of varying sizes, colours and designs, both choosing a smooth ten-incher with a round thick head. She followed that up with a butt-plug and a bottle of her friend's anal lube, confident they wouldn't notice a couple of small squirts.

She returned to her room, gratified and slightly amazed that the 'bot had taken the time to resmooth the bed covers and fold a couple of pairs of jeans which had been laying on her chair. The naked 'bot smiled excitedly and put down the sweater she'd been shaking out, "Oh you found a cock. That looks big."

"It is," said Dawn grinning. She waved the plug, "but I brought this to help."

"What a good idea," said the blonde admiringly. She took the plug from Dawn and twisted it round in her hands, looking over it like it was a precious antique. After a few moments she looked up and at the naked brunette lounging on the bed, "Shall I be Spike or you?"

Whilst there was something appealing about being the one doing the fucking Dawn wanted orgasms and you'd get more of them by being the fuckee. "You be the man," the teen said.

"Shall I do Spike's accent," said the 'bot in an impression of a cockney so bad that Dick van Dyke would have been ashamed.

"Mmnnnn... No," said Dawn definitely. If the 'bot had born the slightest resemblance to the vampire it might have been okay, but having her look like Buffy giving a third-rate impression of a reject from a London gangster movie would be way too weird, even for Dawn.

"Do you want me to put this in?" the 'bot returned to her normal valley accent and waved the butt-plug in front of Dawn.

"Yes," Dawn nodded, "Let me get used to having my butt stretched before you go all the way." 

She rolled onto her back and lifted her legs, pulling them back and apart so her virgin rosebud was on display. The 'bot climbed onto the bed, crawling towards Dawn like an ornithologist approaching a rare Red-cockaded Woodpecker. She reached out to Dawn's hole, using a couple of fingers to pry the cheeks apart further. "Spike used to like me to have this when I would dust his crypt. He used to say it kept my Buffy butt ready for action; which wasn't true; my Buffy butt was always ready for action." She paused speaking her and Dawn felt the hard tip of the toy pressing at her sphincter. "I was a good girlfriend," the blonde 'bot sounded aggrieved as if anyone could have doubted her.

"Oooohhhh," Dawn's mouth opened and her eyes widened as for the first time ever as sex toy was pushed into her anus. It felt kinda funny, like an itch which can't be scratched or like she had just put on a pair of panties that were just a little too small. It was nice though, making her butt tingle and her pussy horny and warm. 

"Is that good?" the 'bot asked and continued to slide the toy in. 

"Ooooohh," Dawn moaned in reply. The blade of the plug pressed down, opening her anal passage, gently stretching the tube and rubbing at nerves the teen never knew she possessed. Her own hand reached down and she began to gently massage her clit, the tender touch of her fingers on her special spot complementing the warm, pleasurable waves of pleasure emanating from her butt. "Ooohhh, that is good," she moaned again.

The plastic hilt pressed itself against her cheeks, the plug as far in it as could manage. The Buffybot sat back up on her knees admiring her handiwork as Dawn kept her legs up so the automaton could get a clear look. The 'bot grinned happily, "We should let that settle, so your ass gets used to it."

"Okay," said Dawn.

"Do you want me to lick your pussy again while we're waiting?" asked the blonde, "Or I could do some ironing and come back once it's done."

"Lick my cunt," said Dawn definitely.

"Okey dokey, sis," sang out the 'bot and buried her face in the teen's shaven pussy.

"Ooohhhh, urrrrhhh," Dawn moaned out in joy. If it had been enjoyable before it was double the bliss now as with every probe of 'bot's tongue the plug vibrated pleasurably. The blonde's tongue pounded hard and fast, sweeping over the soaked slit to pound at the clit and then down again, flying between the lips and washing at the cum soaked flesh between. Each lick was sex squared, making Dawn tremble and squeak. She bounced and fondled her own teen titties, making the nipples hard as the Buffybot's made her pussy wet. Her legs dropped down onto the blonde robots shoulders, quivering and shaking as the bot's head bobbed, her tongue flaying the soaked twat beneath it. The teen's back arched as a wave of ecstasy blew through her, "Ooooh...aaarrrghhh, yesss, ooooohhhhh."

"Mmmnn, mmnnnn," the 'bot slurped at the cunt, a finger joining her tongue to push down into the wet pussy-hole. The young brunette bucked again, her cries loud and passionate. As her ass bounced back on the bed, she could feel the press of the toy in her asshole and it made her almost cum again. The 'bot didn't let up, continuing to tongue the slit and up to the clit, her finger down the hole, diving down as deep as the 'bot could push. 

"Aaaarrrghhh, yesssss, yessss, Goddddd!!!" Dawn cried out in pleasure. Whatever you could say about the 'bot - she was unreasonable cheerful, deeply naive and terrible at helping Dawn study - but she could lap cunt. "Aaaarrrghh," the teen squealed again, "Oh my Goddddd, aaaarrrggghhh."

The Buffybot gave one more lick, a toe curling tonguing that almost sent Dawn to the stratosphere, before lifting her head and looking at Dawn, "I think your ass should be ready now? Do you?"

"You're the expert," said Dawn, though from the wetness of her pussy and itchy horniness of her ass she thought she was.

Buffybot nodded, smiling at the compliment. She quickly got off the bed and picked up the strap-on. Dawn lowered her legs back down to the bed, relaxing as she watched the blonde robot pull the toy up her thighs and adjust it over her pussy, before picking up the bottle of lube, squirting a generous mixture onto her hand before smothering the toy with it. She continued until the toy was literally dripping with lubricant, obviously wanting, for Dawn's first time, as smooth an entry as possible. 

She got back on the bed and Dawn lifted her legs back, reaching under her thighs and easing them towards her head so that she was almost bent double. The 'bot crawled forward and her head dropped. For half a second Dawn thought in frustration the blonde was going to return to licking her pussy, not that the lapping had been anything but great, but she was horny in anal anticipation. But she was wrong, the 'bot teeth gently gripped the flap of the plug. She pulled, using her mouth to ease the toy from the teenage brunette. Dawn gasped in pleasure as the toy exited her. She pulled her legs back even further, showing her faux sister her open hole. "Ooohhh, fuck me, bang me in the ass."

"Sure thing sis," the bot said chirpily. 

Dawn grunted and shuddered, her back bending as the strap-on dildo pressed at her rosebud and then went in. The first four inches of tunnel were easily conquered, the lubed toy flashing down the chute already opened by the plug. The next couple of inches fell in the same thrust, the 'bots momentum driving her forward. Dawn squealed and bucked, two fingers rubbing hard at her pussy as her other hole was devirginised. The blonde pulled back, smiling inanely and drove in again. This time another inch fell to her thrust, the walls retreating back as the toy's tip pushed them apart. Dawn's back bent and she closed her eyes in pleasure, the cock in her ass felt so good, so right, like it belonged. "More, more," she gasped, her fingers rushing over her wet cunt and making it quiver and shake.

"I am a good sister," the 'bot said like it was confirming it to itself. Dawn didn't disagree as the blonde robot pounded forward.

Another inch of dildo was in Dawn, the toy beating back the tight walls and discovering places next before violated. The teen's spare hand shot out and gripped the bedding, pulling it up and ruffling it so that it resembled the dunes of a desert after a sandstorm. She squeaked again, her body lifting as the 'bot pounded forward. Dawn leg's trembled, unable to stay up on there own and she dropped them so they rested on the robot's shoulder. They bounced again as the 'bot slammed in, the lubed toy another inch in. Dawn's finger thrummed over her wet pussy, the lips quivering as she massaged them intensively. 

"Are you okay? Are you enjoy?" the 'bot asked, her voice full of sisterly concern.

"Oh fuck yes, God I'm loving it," the teen squeaked. It was almost all the way in, ten inches of hard plastic filling her ass and it was driving her wild. "Ram my ass, I want it all."

The Buffybot nodded, her hands reaching to grip Dawn's ankles and use them for leverage as she continued to thrust and slam. The ass was opening further, the walls giving way collapsing like Jericho after band practice. The teen shrieked in pleasure as the Buffybot's thighs smacked at her ass, the dildo slamming all the way in. "Ooohhh my... shiiiitttt, fuck me, fuck me."

"I like being a good sister," said the 'bot as she continued to pound Dawn's asshole. "I want to do what you want me to do. We can play a game after this, Clue if you want. Or chess, I know you like chess and you always beat me at that."

"Shut up and fuck me," shrieked Dawn, rocking her own body forward to meet the incoming 'bot thrust. The Buffybot looked a little hurt, and Dawn made a mental resolution to compliment her cooking after they'd had dinner - robots had feelings too. Still, at this moment she wanted the 'bot to concentrate on butt-banging her and not worry about being a perfect sister and more on being a hard core sister fucker (even if they weren't real sisters). Dawn screamed again, as the dildo pounded so hard into her ass her fingers were vibrations it was sending through her.

"Am I doing okay for you? Do you want me to go faster or harder? I can slow down if you like," the Buffybot said cheerfully, quickly recovering from Dawn's shouting at her.

"OOoohhhh yesss, both. Harder and faster. Deeper as well," Dawn gasped, though as the full length of the toy was already vanishing down her ass the latter was an impossibility.

"Okey dokey," the 'bot said cheerily and slammed both quicker and more vigorously, each thrust like a pneumatic hammer pounding into the hole. 

Dawn's body bounced and shuddered, her calves beating at the 'bot's shoulders as her feet waved and jiggled in the air. Her teenage titties were jumping and shaking like two jellies on a plate, her nipples erect and hard with horniness. Her breath came in spurts, her diaphragm moving up and down as she struggled to draw in the oxygen and stars seemed to be exploding in front of her eyes as her brain went into overdrive. the 'bot smiled down, not out of breath or red from exertion, even her hair in place and not wild and wet like Dawn's. The teen screamed in pleasure, she was being fucked by a fucked machine, who'd never tire or stop or care about anything but Dawn's pleasure. It was something Dawn wanted much more than a robot who thought she was her sister. The teen's finger rushed over her cunt, "Fuuckkkk, yeessss, aaaaarrrghhh..."

"If you want me to stop tell me," said the Buffybot. "Otherwise I'll just think you're screaming in pleasure. I don't want to hurt you."

Point noted, thought Dawn. "Just a little harder and faster, aaaaarrrghhh, that's it. If I tell you again ignore me." You had to put parameters on the 'bot, otherwise Dawn would accidentally scream harder and the 'bot would pound so hard she end up in the teen's stomach

"Okay sis, whatever you want," said the 'bot hammering the teen's ass so hard that the bed was rocking like a cork dropped in a bath.

The explosion of pleasure was like nothing Dawn had ever had before. Sure, she had orgasmed, both by herself and when the 'bot had been tonguing her. But neither were like the anal orgasm which almost lifted her off, it was like comparing the Shuttle launch to the Wright Brother's first flight. Her body burned and twisted, her muscles unsure whether they were contracting or relaxing and trying to do both at the same time, as every nerve sung out and whirred. "AAAarrrrghhh," she screamed "Aaaaarrrghhh."

"I'm not going faster or harder," the 'bot confirmed, whilst still going plenty. The brunette screamed again her body arching and twisting, her eyes closed so tightly shut she couldn't open them. The automaton slammed on and on, not pausing or stopping - a Terminator of sex.

The orgasms came thick and fast after that, each one blasting the teen into orbit until it seemed she was perpetually swinging round the earth like a satellite. Her entire body was exploding in pleasure, shuddering and shaking as the 'bot banged into her and drove her to the Moon. The teen's skin was red, the blood pumping through her, so hot she could almost feel herself blistering. And the Buffybot was so serene, a happy smile plastered on her face, which remained as palely white as it always did and without a hair out of place; the 'bot never looked more like her perfect sister than when she was butt-fucking Dawn.

"Aaaaarrrghhh, yesssss, aaarrrggghh," Dawn shrieked and squealed, until her voice was hoarse. Her back bent and stretched, her spine aching. And her muscles were tender and tired, even though she was the one lying on her back. It was worth it for the pleasure, even when her wrist was so sore she had to drop it from her pussy, she was still cumming almost constantly and each orgasm was more than explosive. Her ass might be starting to ache, her hole gaping and the tunnel walls irritated as the lube was burnt away by friction from the hard fucking, but each thrust from the 'bot was orgasmically deep and hard. In some part of her mind Dawn could have stayed like it for ever.

"OOoohhh, aaaaaarrghhh, oooohhh," she came again, her body racked and exhausted. She knew that if she continued she'd be ruined, her ass unable ever to take such pleasure again. Or that Willow would notice she was limping, ask the 'bot, who would stupidly then tell Willow what she'd be doing and be banished to the cellar together with Dawn's chance of another butt-drilling. The teen closed her eyes and forced herself to calm for a second, "That's enough stop."

"Okay," the Buffybot pulled out without complaint. She smiled down at an exhausted Dawn, "Was that okay? Do you want me to do again?"

It would have been so tempting to say yes, but Dawn managed to shake her head. "No, sometime later when Willow and Tara are out again. And don't tell them about this, it's a secret."

"Yes," Buffy nodded enthusiastically, "A sister secret."

"Okay yes," Dawn sighed. She watched as the 'bot got up and unbuckled the toy, "You better give it a quick clean and then I'll put it back."

"Oh yes," said the 'bot, "and then I'll start dinner. It'll be your favourite for my favourite sister."

She wasn't Buffy, but the 'bot did have some good points.

*


End file.
